This invention relates to an apparatus for forming flexible sheet material into rolls, and more particularly to an apparatus for forming newspaper sheets into log shaped rolls having a density capable of providing even combustion for a long duration.
Firm rolls of combustible paper sheet material, commonly called paper logs, are used instead of fuel wood logs in fireplaces and stoves. Combustion of paper logs provides a means of disposing of unwanted waste, conserves costlier or scarcer wood, and provides a means for recycling a waste material into energy. Paper logs, when formed and compacted evenly, can be readily handled and stored, and can provide stable combustion over a prolonged period of time, as compared to the typical flash combustion produced by separated loose sheet, or the unsustained combustion produced by combustible sheet material formed into objects of exceptionally high density, as for instance, a book.
Apparatus for forming flexible sheet material into rolls capable of providing combustion are known in the art. The simplest apparatus for forming paper logs includes a hand cranked shaft rotated in a simple supporting frame. Devices such as this are deficient for forming paper logs having a density which gives even burning because there are no means for compacting or smoothing the roll; this must be accomplished intermittently and manually by the operator. To permit engagement of discontinuous sheets into the roll, and to produce a roll which will maintain its integrity upon removal, it is necessary that sheets be interleaved. With apparatus heretofore known in the art, interleaving of discontinuous sheets is difficult; as one sheet is drawn about the roll, the following sheet must be awkwardly placed within the intersection of the unrestrained trailing edge of the sheet and the outer surface of the roll. In some instances a liquid such as water or hydrocarbon is integrated into the sheet while it is formed into a roll, to either facilitate compaction and integrity of the roll upon its removal from the apparatus, or to provide a combustible residue. The use of a liquid is messy and awkward, and in the case of water, necessitates drying the log before use.
Wolk, in U.S. Pat. No. 3,033,481, filed Feb. 28, 1961, describes a handcranked device for reeling continuous paper tape into a roll formed about a shaft. The device has spring-actuated side plates which serve to even the length of the paper roll by pressing on the cylindrical ends of the roll. Control of the longtitudinal dimension through the spring actuated plates does not have any beneficial effect on the diametrical compaction. Control of the diametrical compaction only results from the tension force in the sheet being wound, which is not controlled by the apparatus.
Christen, Jr. et al. in U.S. Pat. No. 3,964,373 filed Mar. 19, 1975, describe a device having a split-cylinder tray. The tray partially surrounds the handcranked shaft and forms a space which is filled as the sheet is accumulated as a roll about the shaft. Contained within the tray are elongated leaf springs which bear circumferentially against the outer diameter of the roll being formed. The tray only serves the purpose of containing the springs and does not otherwise aid compaction or feeding of sheet into roll.
Butz in U.S. Pat. No. 3,936,007, filed Oct. 3, 1974, discloses an apparatus having a handcranked roll-forming shaft, the ends of which are rotatably mounted in slidable end pieces moving in guides perpendicular to the base. The shaft is thus permitted to translate in a plane perpendicular to the base, opposed by springs within the end piece guides. As a result, when the paper roll is accumulated on the shaft, the outer surface of the roll presses on the base, thereby tightening and compacting the roll. Due to the translation which the shaft undergoes, the device is not readily adapted to being powered by a motor; continuous interleaving and roll formation are not easily achieved by a sole operator.
In the foregoing and other apparatuses, where there is no provision for smoothing the roll, special skill in careful feeding and manual smoothing on the part of the operator is needed to achieve a uniform, smooth, and evenly combusted roll. Where no provision is made for easily interleaving discontinuous sheets, either the operation must be intermittent and the formation of a roll thereby slowed, or an assistant must be employed to help the operator feed the sheets or turn the crank.